JPS59141280A - Gas laser, gas laser amplifier firing method and firing circuit device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and an ignition circuit arrangement for a gas laser, such as a CO2 laser, and a gas laser amplifier, using a plurality of coupled gas discharge paths operated by an axial direct current discharge; For example, gas lasers and gas laser amplifiers comprising multiple folded resonator arrangements and two opposing discharge channels each, the cathodes of the discharge channels being at ground potential and the anodes of the discharge channels having a certain distance from each other. The present invention relates to an ignition method and an ignition circuit device.

In order to reliably ignite the discharge path of a gas laser operated with a gas mixture, the ignition voltage for each individual discharge is generally approximately 2 to 6 times greater than the arc drop voltage required to sustain the gas discharge. must be applied to each individual discharge tube in the path. However, in this case, not only the ignition voltage but also the arc drop voltage range depends on the local characteristics of the discharge path, the gas mixture, and the gas pressure. However, it is often relatively difficult to ignite a gas mixture with favorable laser characteristics. In order to avoid such ignition difficulties, relatively high ignition voltage pulses are generally used. For this purpose, it is known, for example, to connect a low-power auxiliary power supply in series with the actual power supply in order to generate this ignition voltage pulse. During power-on, the voltage in the auxiliary power supply is accumulated, the laser is ignited, and when the laser ignition creates a load, the voltage in the auxiliary power supply is eliminated and the original power supply is switched on via a suitable diode circuit. Receives power supply energy. , in which case the regulation of the discharge current is carried out via a triode with a high voltage hook. Among other drawbacks, this configuration is technically complex.

In the case of high-voltage power supplies controlled by thyristors, high firing voltages can be generated by reducing the firing angle of the thyristor for a short time. However, both configurations exhibit particular drawbacks. That is, although a sufficient smoothed DC voltage is required for continuous operation of the laser, such DC voltage or the smoothing capacitor used for it may interfere with the generation of a sufficiently steep ignition pulse. It is. This is because the smoothing capacitor is charged according to a fixed function, and the rate of voltage rise decreases as the charging depth increases. Since the individual discharge channels are conditioned by different factors and fire at different voltages, the course of the firing voltage pulse is relatively flattened, so that the firing is staggered in time; As a result, if the distance between the anodes of discharge paths facing each other is small, ignition may become difficult. Specifically, when there is a significant time lag between the anodes involved, there will be a potential difference of the magnitude of the difference between the operating voltage and the arc drop voltage, and this potential difference will cause a gas discharge to occur between the anodes. , the laser will result in significant damage. In order to reliably avoid such a phenomenon using conventionally known means, the only way is to arrange the individual anodes at a sufficiently large distance from each other. However, this is a significant disadvantage, especially in situations where the overall length of a laser of this type is required to be as short as possible.

In order to overcome the ignition difficulties described above, it has already been proposed to introduce the individual gas components of the gas mixture used into the discharge path one after another.

In this case, start with the gas component that is easiest to ignite and then mix the other gas components to maintain the discharge until the mixture has the desired mixing ratio under normal operating pressure. (German Patent Application Publication No. 3113591).

If such an ignition type is adopted, it is no longer necessary to increase the ignition voltage pulse as in the case of ignition of a mixture that is already in an optimal state. This is in part because the ignition voltage for the most easily ignited gas may be on the lower side of the normal arc drop voltage of the desired gas mixture.

However, experience has shown that this type of ignition is extremely time consuming. In particular, lasers can be turned on in a short time.
・The disadvantage is that it cannot be turned off.

It is an object of the present invention to provide a gas laser and a gas laser using a plurality of coupled gas discharge paths operated with an axial direct current discharge, which eliminates the defects as mentioned above and thus avoids damage to the laser. A method and circuit device for igniting an amplifier are provided.

The basic object of the present invention is to create a system of the type described in the above description, which requires only a small amount of technical effort and expense, has a low failure rate, and ensures a high ignition reliability with an optimally short overall length of the laser beam. An object of the present invention is to provide a method and circuit device for igniting a gas laser and a gas laser amplifier.

According to the present invention, this problem is solved as follows.

In other words, a high-voltage transformer controlled by a thyristor is used, connected downstream to the high-voltage transformer with a rectifying device and a smoothing device for the high voltage generated, and the following method steps are carried out.

The laser can be activated by switching on the high-voltage power supply by driving the cyrisk on the primary side of the associated high-voltage transformer with an adjustable firing angle using a control voltage (U-stl). on the secondary side of the high-voltage transformer, controlling a smoothing capacitor provided after the full-wave rectifier in order to smooth the pulsed DC voltage delivered from the full-wave rectifier. Voltage(
U -stl ) to a voltage that is at most 95% of the ignition voltage of the individual partial discharge paths of the laser, and synchronized with the zero crossing of the sinusoidal supply voltage to a peak value (
The firing angle of the thyristor is reduced to α=D for a short time interval using a control voltage pulse configured as a neat pulse with U −gt2), with a steep course in the initial phase. Charges the smoothing capacitor with an ascending slope, producing a short voltage pulse that exceeds the ignition voltage of the individual partial discharge paths of the laser, and which, because of its steep rising edge, overshoots all involved partial discharge paths. ignition of the laser in a short time and with high accuracy in all partial discharge paths of the laser, and after the ignition pulse (U-8t2) all involved parts Assuming that the discharge path is ignited, otherwise the supply voltage is immediately cut off to protect the laser.
setting the firing angle of the thyristor with an adjustable control voltage (u-sTs) to a value corresponding to the respective required discharge current for the laser;
Each of the above steps is performed within an adjustable, relatively short period of time after laser activation.

A circuit device for implementing the ignition method of the present invention is configured as follows. That is, a thyristor control device having a pulse blocking device, a full-wave rectifier, and a plurality of discharge paths connected in parallel are provided, and the thyristor control device is driven from the input side with a sinusoidal power supply voltage. A high-voltage transformer is driven through the output side, a smoothing capacitor is connected downstream to the full-wave rectifier, and a time-limiting element consisting of a series connection of a diode, a resistor, and a capacitor, and a relay in parallel with the capacitor is installed. a synchronous element is provided, supplying voltage to the timing element via the break contact of the ON switch, and being supplied with a synchronous pulse from the thyristor control device, when the make contact of the relay is closed, in the synchronous element; the sync pulse is connected to ground via a resistor, while when the make contact opens, the sync pulse is applied via the resistor to the base of a transistor acting as a negating element, a differential consisting of a capacitor and a resistor; A bistable multivibrator is provided, in which the synchronizing pulse that is negated by the transistor is differentiated by a differentiating element and sent through a diode through which only the positive needle pulse passes;
Trigger the bistable multivibrator via the diode, reset the bistable multivibrator to the L state via the break contact of the switch ON key and the resistor, and control the circuit driven by the bistable multivibrator as necessary. The necessary control voltage (U-Stl) is generated by the circuit section using a resistor, a regulating resistor and a diode, and the necessary control voltage (U-Stl) is generated by the circuit section using a capacitor. (U − St2 ), the circuit section generates the necessary control voltage (tr −5t3) using a regulating resistor, and the capacitor is connected in parallel to the regulating resistor and the tag of the regulating resistor. and two voltages (U − St
2, U-8t3) is supplied to the control input side of the thyristor control device via a diode, and the control voltage (U
-8t1) is added to the control input side via a diode, detection resistors are inserted and connected in the cathode branch paths of all discharge paths, and relays are connected in parallel to these detection resistors. A circuit section is provided in which the break contacts belonging to these relays are connected in parallel to the ignition pulse blocking device through the break contacts of the relays, and further connected to earth in series with the timer element, and the break contacts of the timer element are connected in series to the earth. The ignition pulse blocking device is installed in the ignition pulse blocking device and, by operation of the switch ON key, releases the ignition pulse blocking device for the thyristor of the thyristor control device and keeps the relay in the operating state for a time that depends on the capacitance of the capacitor. , the synchronous pulse is conducted to earth via the make contact, the supply voltage is applied via the resistor and the tap of the regulating resistor and the diode to the control input side of the thyristor control device, and the thyristor is connected to the control voltage adjusted by the regulating resistor. (U
-Stl ) or the firing angle derived from the control voltage (u -5t1), charges the smoothing capacitor with the output voltage derived from the control voltage (υ-5t1), and after discharging the capacitor, the relay is restored, the break contact closes and ignition control is engaged, while the make contact opens and the next synchronizing pulse, precisely with the zero crossing of the sinusoidal supply voltage, tri-powers the transistor and doubles the The stable multivibrator is triggered via an inserted differential generator to switch from the L state to the H state, producing an abrupt voltage change of peak value (U −5t2 ) with a steep rising edge, and Initially, the voltage change is completely transmitted to the control input side of the thyristor control device via the capacitor and the diode, and the voltage change completely turns on the thyristor, so that the firing angle α−〇) increases the firing voltage much further. The voltage change exceeds the ignition voltage pulse, and as the capacitor is charged, the DC voltage applied to the capacitor (
Hm) and the control voltage (u
-St3) from the tag of the regulating resistor via the diode to the control input side of the thyristor control device so that the required discharge current flows through the existing discharge path, in which case all discharges The road is lit,
It is assumed that all sensing resistors produce a voltage drop that activates their respective relays, whereas if at least one of the discharge paths is not firing, the corresponding relay does not activate. If the break contact belonging to the relay does not open and the timer element is not cut off from the voltage in a timely manner, the relay operates after the set time has elapsed, and the ignition pulse blocking device is activated by the relay through the break contact. It is characterized by assuming that the high voltage is cut off once again.

Next, the present invention will be explained in detail with reference to the drawings with reference to embodiments. The figure shows a circuit arrangement for implementing the method of the invention.

In FIG. 1, the input side of a thyristor control device 1 with a pulse blocking element 2 is driven by a sinusoidal alternating current voltage, and the output side of the thyristor control device 1 drives a high-voltage transformer 3. A full-wave rectifier 4 is connected downstream of the high-voltage transformer 3. The output voltage of this full-wave rectifier 4 is smoothed to a required degree by a smoothing capacitor 04. The full-wave rectifier 4 includes discharge paths 5,1-5. connected in parallel.
connected to n.

We will therefore first explain the method according to the invention for igniting a laser of the type described, with reference to the illustrated circuit arrangement, in connection with the arrangement of the components and then in terms of the temporal or circuit-technical cooperation of the components. This will be explained in detail in relation to work.

The circuit device is composed of the following constituent groups. Two time-limiting elements 6: The time-limiting elements 6 are composed of a diode D1 and a resistor R.
1 and a capacitor C1 connected in series, and a resistor 1 connected in parallel to the capacitor C1. The timing element 6 is
Via the break contact of the switch ON key S, ie when the pulse blocking element 2 of the thyristor control device 1 is switched off, it is supplied with voltage.

One synchronous element 7゜The synchronous element 7 has a cyrisk control device 1.
A synchronization pulse is supplied from In the synchronizing element 7, the synchronizing pulse is connected to ground via the resistor R2 when the make contact 1,1 of the relay 1 is closed. When the make contacts of the other relay 1 open, a synchronizing pulse is applied to the base of the transistor T1 via the resistor R3. Transistor T1 acts as a negative element.

One differential element 8゜Differential element 8 is capacitor C2 and resistor B5
It consists of The synchronous pulse negated by the transistor T1 is differentiated by the differentiating element 8 and transmitted via the diode D2. Diode D2 allows only the needle pulse of positive polarity to pass.

One bistable multipipe generator 9 The bistable multivibrator 9 is driven via the differential element 8, and the switch is turned on.
It is reset to the L state via the break contact of the key 8 and the resistor R10.

-Circuit unit 10° The circuit unit 10 is driven by the bistable multivibrator 9 and generates a control voltage to be described later. That is, U -8tl is generated using resistor R8, adjusting resistor R9 and diode D4, U -8t2 is generated using capacitor G6, and IJ -Si3 is generated using adjusting resistors R6 and R7. However, capacitor C3 is in parallel with the taps of resistor R6 and resistor R7, and two voltages U-Si2 and U-Si2
is connected to the thyristor control device via diode D3.
It is applied to the control input side 12. The other control voltage U −+3t1
is applied to the control input 12 via the diode D4.

Circuit section 11o for single-ignition control This circuit section controls all the discharge paths 5, 1 to 5. Detection resistors R11 to Rm inserted in the cathode branch path of n and these detection resistors R11
It has 11~Km in parallel to ~Rm. 11 to the break contact belonging to the relay 11~Km,
1~Km, 1 are connected in parallel and appear on the one hand connected to the ignition pulse blocking element 2 via 1, 2 to the break contacts of 1 to the relay, and on the other hand to the time relay 2 in series is connected to ground. The break contacts of 2 in the time relay 2,1 are in the ignition pulse blocking element 2.

This circuit arrangement is designed as follows. That is, when the switch ON key S is operated and the ignition pulse blocking device 2 is thereby released, the timer element 6 is cut off from the power supply voltage. The relay then remains active for a time that depends on the capacitance of the capacitor C1. As a result, on the one hand, the synchronizing pulses taken off from the Cyrisk control device 1 escape to earth via the make contacts 1,1, and on the other hand, the supply voltage U-V is It is applied to the control input 12 of the thyristor control device 1 via a tap and a diode D4.

The thyristor is driven with a firing angle derived from the control voltage U -8t1 or the control voltage U -Stl regulated via the regulating resistor R9, and the smoothing capacitor C4 is driven by the output voltage resulting from the control voltage U -Stl. It will be charged. After proper discharge of capacitor C1, relay 1 is delayed and the break contacts 1 and 2 are closed, resulting in ignition control being applied. On the other hand, due to the opening of 1.1 on the make contact, the next synchronization pulse drives transistor T1 exactly at the zero crossing of the sinusoidal supply voltage. Transistor τ1
The output signal is differentiated by a downstream differential element 8 and applied to the input side of a bistable multivibrator 9. As a result, the bistable multivibrator 9 switches from the L state to the H state, and a higher output voltage is generated at the output side of the bistable multivibrator 9. This output voltage corresponds to the value of control voltage U-19t2. This drastic voltage change is first sent to the thyristor control device 10 control input @12 via capacitor C3 and diode D3 (in the form of a -$ pulse). In this way, the sirisk is completely turned on (ignition angle α; 0). As a result, an ignition voltage pulse with a steep course occurs on the output side. This ignition voltage pulse is applied to all associated discharge paths 5,
1-5. n ignition voltage range is passed in a very short time and thus the laser ignites with high accuracy. Due to the charging of the capacitor C3, the direct voltage (H-potential) coming from the multivibrator is blocked by the capacitor C3 and the control voltage U regulated by the regulating resistors R6, R7.
-8t3 is applied via a diode D3 to the control input 12 of the cyrisk control device v,1. In this way, the cyrisks are connected to the discharge paths 5.1 to 5. It is driven by an ignition angle that produces the required discharge current on the output side via n. In that case, all discharge paths 5.1-5. n are fired and therefore 11 to each corresponding relay.
〜Km to all break contacts by operating 11
, 1 to Km, 1 is assumed to occur at all detection resistors R11 to Bo. However, discharge paths 5.1-5. When one of n does not fire, +o does not operate on the corresponding relay Kll~, and the break contact belonging to it does not fire +o, 11,1~Km, 1
remains closed. So after an adjustable time,
The relay 2 operates, the relay 2 opens the corresponding break contact 2,1, the ignition pulse blocking element 2 is cut off again, and thus finally the high voltage is cut off.

[Brief explanation of the drawing]

The figure is a block circuit diagram of a circuit arrangement implementing the ignition method of the invention. 1... Thyristor control device, 2... Pulse blocking element, 3... High voltage transformer, 4... Full wave rectifier, 5.
1-5. n...discharge path, 6...timing element, 7...
Synchronous element, 8... Differential element, 9... Bistable multivibrator, 10... Control voltage generation circuit section, 11...
・Ignition control, 12...Control input side, C4...Smoothing capacitor, 111~R+a...Detection resistor, S...
・Switch ON key, Kl, Kl, 1. [11~Km. K2...Relay. Agent: Mitsuyoshi Ezaki Agent: Mitsufumi Ezaki

Claims (2)

[Claims] (1) A method for igniting gas lasers and gas laser amplifiers using a plurality of coupled gas discharge paths operated by an axial direct current discharge, in which the associated high-voltage transformer (3
) is connected to the control voltage (U-
5, 1) by turning on the high-voltage power supply, driven with an adjustable firing angle, and in the secondary full of the high-voltage transformer (3). In order to smooth the pulsed DC voltage sent out from the full-wave rectifier (4), a smoothing capacitor (C4) thrown behind the full-wave rectifier (4) is connected to the control voltage (U - Stl ).
a step of charging up to a voltage which is K dependent and is at most about 95% of the ignition voltage of the individual partial discharge paths (5) of the laser and a peak value (U -s ) synchronized with the zero crossing of the sinusoidal supply voltage
Using a control voltage pulse configured as a needle pulse with t2 ), the firing angle of the thyristor is reduced to α = 0 for a short time interval, with an upward slope with a steep course in the initial phase. It charges the smoothing capacitor (C4) and produces a short voltage pulse that exceeds the ignition voltage of the individual partial discharge path (5) of the laser, which voltage pulse, due to its steep rising edge, Partial discharge path (5)
ignition voltage range of 100% over a short period of time so that all partial discharge paths (5) of the lasers are ignited with high accuracy, and after the ignition pulse (u-5t2),
The respective required discharge tR for the laser, provided that all involved partial discharge paths (5) are ignited and, if not, the supply voltage is immediately interrupted to protect the laser. Adjustable control voltage (to the value corresponding to
tJ - Sr1) to set the firing angle of the thyristor, and each of the above steps is performed within an adjustable, relatively short period of time after starting the laser. arc method. (2) In the ignition circuit device for gas lasers and gas laser amplifiers using a plurality of coupled gas discharge paths operated by axial direct current discharge, a thyristor control device (1) having a pulse blocking device*(2); , full wave rectifier (4)
and a plurality of discharge paths (5) connected in parallel, the thyristor control device (1) is driven with a sinusoidal power supply voltage from the input side, and the thyristor control device (1) To drive the voltage transformer (3), full wave rectifier fj
Connect a smoothing capacitor (C4) to it(4) afterwards, and connect a diode (Dl), a resistor (R1), and a capacitor (C1).
series connection and capacitor ((31)K parallel relay (
A timing element (6) consisting of K1) is provided, voltage is supplied to the timing element (6) via the break contact of the ON switch (8), and a synchronizing pulse is supplied from the thyristor control device (1). A synchronous element (7) is provided, and the make contact (
K1,1) is closed, in the synchronous element (7),
The transistor (T1) acts as a negation element so that the synchronization pulse is connected to ground through the resistor (R2), and on the other hand when the make contact (K1,1) opens, the synchronization pulse is connected to the ground through the resistor (R2). A differentiating element (8) consisting of a capacitor (C2) and a resistor (R5) is provided, and the synchronizing pulse negated by the transistor (T1) is differentiated by the differentiating element (8) K, and the positive polarity is It is sent out via a diode (D2) that passes only the needle pulse, a bistable multi-by-break (9) is provided, and a diode (
Trigger the bistable multivibrator (9) via D2) and the bistable multivibrator (9) via the break contact of the switch ON key (8) and the resistor (R10).
is reset to the L state, and a circuit section (10) driven by a bistable multivibrator (9) is provided for generation of the necessary control voltage, consisting of a resistor (R8), a regulating resistor (R?) and a diode ( D4
), the circuit section (10) generates the necessary control voltage (u - Stl ), and the circuit section (10) generates the necessary control voltage (υ-5t2) using the capacitor (C3). ), and using adjustment resistors (R6, R7), the circuit section (10)
The necessary control voltage (U-8t3) is generated, and the capacitor (C6) is connected to the resistor (R6) and the resistor (R7).
) are connected in parallel to the taps of two voltages (U −8t2
, U-E3t3) is supplied to the control power (12) of the thyristor control device O) via the diode (D3), and the control voltage (U-stl) is supplied to the control voltage (U-stl) via the diode (D4).
in addition to the control input side (12) via the detection resistor (
R11~Rm) are inserted and connected, and relays (K11~Rm) are connected in parallel to these detection resistors (R11~Rm).
Km) is connected to the ignition control circuit section (11), and the break contacts (K
11,1~xm,i) are connected in parallel and connected via the break contact (x 1.2 ) of the relay (K1) to the ignition pulse blocking device (2) and indeed in series with the timing element (K2). Connect to ground and break contact (K
2.1) is installed in the ignition pulse blocking device (2), and by operating the switch ON key (Fi), the ignition pulse blocking device (2) for the thyristor of the thyristor control device (1) is released, and the capacitor The relay (K1) is kept in operation for a time depending on the capacity of (C1), the synchronizing pulse is conducted to earth via the make contact (K 1.1 ), and the supply voltage (U-V) is In addition to the control input (12) of the thyristor control device (1) via the resistor (R8) and the tap of the regulating resistor (R9) and the diode (D4), the thyristor is controlled by the regulating resistor (R9). voltage (U-Stl) or control voltage (u-8jl
), the smoothing capacitor (C4) is charged with the output voltage derived from the control voltage (U-8t1), and after discharging the capacitor (C1),
The relay (K1) is restored and the break contacts (K 1, 2
) is closed so that the ignition control is activated, while the make contact (K 1,1 ) is opened and the next synchronizing pulse is activated by the transistor (
T1) and the bistable multi-bi break (9) via the inserted differential element (8),
Switching from the L state to the H state, the capacitor (03) and the diode (D3) are initially completely suppressed by a sudden voltage change of the peak value (ti -5t2) with a steep rising edge. Through the thyristor control device (1)
The voltage change completely turns on the thyristor (firing angle α = 0), causing the voltage change to generate a firing voltage pulse that is much higher than the firing voltage, and As the capacitor (C3) is charged, the capacitor (C3) blocks the applied DC voltage (H potential),
The control voltage (tr
-8t3) from the tap of the regulating resistor (R7) via the diode (D3) to the control input (12) of the thyristor control device (1) so that the required discharge current follows the existing discharge path. in which case all discharge paths are fired and all sensing resistors (R1
1~Rm), and the corresponding relay (K11~Km)
) is assumed to occur, and on the other hand, if at least one of the discharge paths (5) is not ignited, the corresponding relay (+n
) does not operate, and the break contact (x
11,1~Kmj) does not open and the timed confectionery (K2) is not timely cut off from the voltage and the set time elapses.
The relay (K2) operates and the break contact (K2,1
), the ignition pulse blocking device is again blocked by a relay (K2), and the high voltage is cut off.